Anti-glomerular basement membrane autoantibodies against different target antigens are associated with disease severity  Juan Zhao, Zhao Cui, Rui Yang, Xiao-yu Jia, Ying Zhang, Ming-hui Zhao  Kidney International  Volume 76, Issue 10, Pages 1108-1115 (November 2009) DOI: 10.1038/ki.2009.348 Copyright © 2009 International Society of Nephrology Terms and Conditions

Figure 1 The frequencies of sera against α1–α5(IV)NC1 in each group of patients with different renal functions. Group A, mild renal damage; Group B, moderate renal damage; Group C, severe renal damage. Kidney International 2009 76, 1108-1115DOI: (10.1038/ki.2009.348) Copyright © 2009 International Society of Nephrology Terms and Conditions

Figure 2 The types of target antigens recognized by anti-glomerular basement membrane (GBM) autoantibodies compared among normal individuals and patients with different levels of renal function. The x axis represents the four groups, including natural autoantibodies against GBM and sera of patients in groups A, B, and C. The y axis represents the frequency of autoantibodies against different types of target antigens, from one type to all five types of α1–5(IV)NC1. NAA, natural autoantibody. Group A, mild renal damage; Group B, moderate renal damage; Group C, severe renal damage. Kidney International 2009 76, 1108-1115DOI: (10.1038/ki.2009.348) Copyright © 2009 International Society of Nephrology Terms and Conditions

Figure 3 The level of anti-glomerular basement membrane (GBM) autoantibodies against α1–α5(IV)NC1 in each serum from patients with different levels of renal function. The diamonds represent the absorbance value of autoantibodies in each patient. The bars indicate the mean absorbance values. The mean absorbance value of anti-GBM autoantibodies against α3(IV)NC1 was significantly higher than that against α1, α2, α4, and α5(IV)NC1 in each group. Kidney International 2009 76, 1108-1115DOI: (10.1038/ki.2009.348) Copyright © 2009 International Society of Nephrology Terms and Conditions

Figure 4 The mean level of anti-glomerular basement membrane (GBM) autoantibodies against α1–α5(IV)NC1 compared among patients with different levels of renal function. The mean absorbance values of anti-GBM autoantibodies to α1–α5(IV)NC1 showed an increasing tendency from group A to group C. The regression analysis showed that only the level of autoantibodies against α3(IV)NC1 was an independent risk factor for a higher serum creatinine in patients on diagnosis (r=0.377, P=0.042). Kidney International 2009 76, 1108-1115DOI: (10.1038/ki.2009.348) Copyright © 2009 International Society of Nephrology Terms and Conditions

Figure 5 Cross-reaction of autoantibodies against α1, α2, α3, α4, and α5(IV)NC1 measured by antigen inhibition ELISA.y axis: the mean of absorbance value (OD) of a serum bound with the antigen coated in the microtiter plates. x axis: different concentrations of the inhibitors of α1–α5(IV)NC1 for preincubation with the serum. (a) Reaction of a serum with α1(IV)NC1 inhibited by α1–α5(IV)NC1; (b) reaction of a serum with α2(IV)NC1 inhibited by α1–α5(IV)NC1; (c) reaction of a serum with α3(IV)NC1 inhibited by α1–α5(IV)NC1; (d) reaction of a serum with α4(IV)NC1 inhibited by α1–α5(IV)NC1; and (e) reaction of a serum with α5(IV)NC1 inhibited by α1–α5(IV)NC1. Kidney International 2009 76, 1108-1115DOI: (10.1038/ki.2009.348) Copyright © 2009 International Society of Nephrology Terms and Conditions